The conformational analysis of saturated heterocycles. Part LVI. Substituent effects in the conformational equilibria of spiro-oxazolines

Abstract

The effects on the conformational equilibria of cyclohexanespiro-4′-oxazolines of 2′-substituents of variable electronic effect and steric size has been examined: surprisingly all exist in the N-equatorial conformation. Possible explanations are given. 1,3-Dioxan-5-spiro-4′-oxazolines favour the N-equatorial conformation by a large factor, as expected.